The quadratic equation whose sum of the roots is 11 and sum of squares of the roots is 61 is

The quadratic equation whose sum of the roots is 11 and sum of squares of the roots is 61 is
  1. $x^2+11 x-30=0$
  2. $x^2+11 x+30=0$
  3. $x^2-11 x-30=0$
  4. $x^2-11 x+30=0$

Solution

Let $\alpha$ and $\beta$ are roots of quadratic equation $\therefore \alpha+\beta=11$ and $\alpha^2+\beta^2=61$ $\Rightarrow(\alpha+\beta)^2-2 \alpha \beta=61$ $\Rightarrow 121-2 \alpha \beta=61 \Rightarrow \alpha \beta=30$ $\therefore$ Quadratic equation is $\begin{aligned} & \mathrm{x}^2-(\alpha+\beta) \mathrm{x}+\alpha \beta=0 \\ & \mathrm{x}^2-11 \mathrm{x}+30=0\end{aligned}$

Asked in: AP EAMCET 2022 (08 Jul Shift 1)

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